Just what is Tony Abbott up to with his decision to put the Greens last on Liberal how-to-vote cards around the country?

While the tactic is not unexpected – he’s been signalling he would do this since the Victorian Liberals took a similar line in the 2010 state election – it runs counter to the past approach of causing maximum destabilisation for Labor.

It seems Abbott has joined Rupert Murdoch’s The Australian in wanting to see the Greens “destroyed at the ballot box”. In case there was any doubt that Murdoch is still keen on that outcome, today’s Daily Telegraph editorial fulminates that the minor party’s “vision for Australia is more aligned with former communist bloc nations than anything with which mainstream Australia is familiar. The Greens are, to put it simply, a party of far-left clowns.”

In a similar vein, right-wing populist MP Bob Katter welcomed Abbott’s decision, telling reporters that “the environmentalist movement … has turned into a cancer and has to be cut out”.

Like the Victorian Liberals, Abbott is painting his move as a matter of principle against political extremism, as well as to minimise the chance of minority government. He has already promised he won’t participate in a minority administration. In typical style, he has challenged Kevin Rudd to “be man enough” to do the same; Rudd gladly accepted the challenge, but only on majority rule.

Yet the only practical outcome of Abbott’s course is to increase the chance of Labor forming a majority government – if the Greens’ Adam Bandt loses Melbourne, the only seat that could be affected.

Bandt has been a strong local MP and expertly mobilised support among not just inner-city voters the Greens typically attract, but a wider layer of traditional Labor voters disappointed by the major party. With the Greens polling well below their 2010 peak, a trend that continues despite the refugee issue re-energising their base, Bandt needs to pull off a stunning upset to win.

Psephologists Peter Brent and Antony Green have both laid out the electoral calculus. Two recent polls have pointed to diametrically opposed results, one showing the primary tracking downwards, and the other (perhaps implausibly) showing him almost winning on primaries.

Should Bandt lose, however, it would be a pyrrhic victory for Abbott, with one hostile left-wing MP replaced by another, Labor’s Cath Bowtell.

There is similarly no chance that the ALP will preference its conservative opponents ahead of the Greens, especially given Labor’s dependence on the minor party’s preferences in both houses. With Rudd bringing Labor within sight of victory, it has no interest in getting involved in Abbott’s preferences game.

For Abbott, there is the additional danger that the logic of his position is exposed. In effect, he is saying that far right micro-parties, some that flirt more or less openly with fascist policies, are “in principle” preferable to the Greens.

It is this logic that reveals what is really going on here. Abbott is the leader the Liberals installed to reinvigorate their core support base, a mixture of right-wing social conservatives and IPA-style market fundamentalists. Yet the support for this agenda in voter land is far too narrow to win an election. Even many conservative voters prefer policies well to the left of the LNP’s, and Abbott remains a deeply disliked opposition leader.

His only saving grace was to be up against the “old Labor” project under Gillard. Because that project exposed the decline of Labor’s traditional institutions, it was easy enough for the party to get tied in knots trying to position itself as anti-Greens while at the same time being in a formal alliance with them. With Labor engaging in anti-Greens histrionics, Abbott could escape scrutiny.

Rudd’s return has neutralised this advantage and started to expose the inconsistency between Abbott’s small target image for swinging voters and the right-wing agenda he relies on internally. It means he no longer looks the safe pair of hands ready to take over after a period of disastrous ALP government.

The Liberals have not only agreed to use official Treasury figures to cost their policies, they have also edged away from past commitments to make massive budget cuts to eliminate the deficit. This must be unsettling to many hard core Liberals, and Abbott is most likely trying to deal with that disappointment by reaffirming his right-wing credentials. It suggests the Liberals are far less confident they have the election sewn up than many commentators argue.

Abbott’s attack on the Greens might go some way to addressing internal issues, but it also makes obvious the weakness of his overall position. This is a paradox not just in his tactical choices but in the real-life tension between Liberal Party dynamics and the task of trying to win enough votes to form government. It is a paradox that will hinder Abbott’s electoral efforts much more than it helps them.